1. Technical Field
The present device relates generally to horticultural and agricultural lighting systems used in developing and growing plants in controlled environments.
2. Discussion of Related Art
Indoor gardens, green houses, hydroponics systems, and isolated carbon dioxide growing chambers demand careful regulation of temperature, light, hydration, nutrients, and humidity. In these controlled environments the grower must provide adequate light intensity, which is usually accomplished using an HID grow lamp in cooperation with a remote HID lamp ballast that is located within a couple feet of the HID grow lamp.
The most common HID grow lamps are high pressure sodium and metal halide. Metal halide lamps work well to generate the “blue” spectrum, but also produce well in the “orange-red” spectrum. Metal halides are best suited as a primary light source (if little or no natural sunlight is available) and are excellent for plant growth. High pressure sodium lamps produce primarily in the “orange-red” spectrum. The high pressure sodiums are the best available lamps for secondary or supplemental lighting (used in conjunction with natural sunlight). The “orange-red” type of light promotes flowering/budding/fruiting in plants. High pressure sodium lamps are ideal for greenhouse or commercial growing applications. However, one significant drawback is the heat generated by these grow lamps. Without cooling, the lamps will prematurely fail. Due to the extreme heat, any electronics located in close proximity to the grow lamp will also prematurely fail.
Both the metal halide lamps and the high pressure sodium lamps require high voltage power to ignite the lamps and maintain lumen output. Commonly, the high voltage power supply is referred to as a lamp ballast. These lamp ballasts convert the standard 110 volt or 220 volt electrical service power to high voltage electrical power that meets the requirements of the metal halide and high pressure sodium lamps. The lamp ballasts are often housed a safe distance from the grow lamp in separate aluminum extruded cases, with a power cord connecting the grow lamp to the lamp ballast.
Lamp ballasts suffer from temperature sensitivity in that excessive temperatures cause premature failure of the electronic components, leading to decreased performance. Because of the heat generated by the grow lamp, the lamp ballast must be thermally isolated in order to prevent premature failure. Generally, the horticulture light fixture with the grow lamp is sold separately from the lamp ballast assembly and the end-user connects the two via a power cord.
Previously integrating the lamp ballast into the horticulture light fixture was not feasible due to the high temperatures generated by the grow lamp and the relatively low temperature failure rates of the ballast. If installed too close to the grow lamp, the lamp ballast will fail prematurely due to the heat produced by the lamp and absorbed by the ballast.
U.S. Pat. No. 6,595,662 to Wardenburg (2003) teaches a horticulture light fixture benefiting from a sealed forced air or passive cooling system. The passive or active cooling of the grow lamp prolongs the life of the lamp while isolating the growing environment from the excessive heat generated by the grow lamp. The Wardenburg horticulture light fixture requires a remote lamp ballast to ignite and power the grow lamp.
An ideal horticulture light system would be constructed and arranged having the lamp, lamp ballast, and reflector integrated as a single structure that, preferably, is thermally isolated from the growing environment. Prior attempts to integrate the lamp ballast into the horticulture light fixture have failed because excessive heat produced by the grow lamp was absorbed by the lamp ballast, causing premature failure of the lamp ballast. Lamp ballasts are sensitive to heat; and, as the operating temperature increases, performance and longevity decrease.
3. Objects and Advantages
There are several objects and advantages of the present device:                a) to provide a horticulture light system that integrates the grow lamp and lamp ballast into a single easy-to-install fixture;        b) to provide an integrated horticulture light system wherein the lamp ballast does not suffer from premature failure due to absorption of heat generated by the grow lamp;        c) to provide an integrated horticulture light system wherein the lamp ballast is thermally isolated from the grow lamp enclosure by an air gap.Still further objects and advantages will become apparent from consideration of the following description and drawings.        